Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <unistd.h>
9#include <time.h>
10#include <sys/time.h>
11#include <signal.h>
12#include <errno.h>
13#include "user_util.h"
14#include "kern_util.h"
15#include "user.h"
16#include "process.h"
17#include "kern_constants.h"
18#include "os.h"
19
20/* XXX This really needs to be declared and initialized in a kernel file since
21 * it's in <linux/time.h>
22 */
23extern struct timespec wall_to_monotonic;
24
25static void set_interval(int timer_type)
26{
27 int usec = 1000000/hz();
28 struct itimerval interval = ((struct itimerval) { { 0, usec },
29 { 0, usec } });
30
31 if(setitimer(timer_type, &interval, NULL) == -1)
32 panic("setitimer failed - errno = %d\n", errno);
33}
34
35void enable_timer(void)
36{
37 set_interval(ITIMER_VIRTUAL);
38}
39
40void disable_timer(void)
41{
42 struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
43 if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
44 (setitimer(ITIMER_REAL, &disable, NULL) < 0))
45 printk("disnable_timer - setitimer failed, errno = %d\n",
46 errno);
47 /* If there are signals already queued, after unblocking ignore them */
48 set_handler(SIGALRM, SIG_IGN, 0, -1);
49 set_handler(SIGVTALRM, SIG_IGN, 0, -1);
50}
51
52void switch_timers(int to_real)
53{
54 struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
55 struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
56 { 0, 1000000/hz() }});
57 int old, new;
58
59 if(to_real){
60 old = ITIMER_VIRTUAL;
61 new = ITIMER_REAL;
62 }
63 else {
64 old = ITIMER_REAL;
65 new = ITIMER_VIRTUAL;
66 }
67
68 if((setitimer(old, &disable, NULL) < 0) ||
69 (setitimer(new, &enable, NULL)))
70 printk("switch_timers - setitimer failed, errno = %d\n",
71 errno);
72}
73
74void uml_idle_timer(void)
75{
76 if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
77 panic("Couldn't unset SIGVTALRM handler");
78
79 set_handler(SIGALRM, (__sighandler_t) alarm_handler,
80 SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
81 set_interval(ITIMER_REAL);
82}
83
84void time_init(void)
85{
86 if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
87 panic("Couldn't set SIGVTALRM handler");
88 set_interval(ITIMER_VIRTUAL);
89 time_init_kern();
90}
91
92unsigned long long os_nsecs(void)
93{
94 struct timeval tv;
95
96 gettimeofday(&tv, NULL);
97 return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
98}
99
100void idle_sleep(int secs)
101{
102 struct timespec ts;
103
104 ts.tv_sec = secs;
105 ts.tv_nsec = 0;
106 nanosleep(&ts, NULL);
107}
108
109/* XXX This partly duplicates init_irq_signals */
110
111void user_time_init(void)
112{
113 set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
114 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
115 SIGALRM, SIGUSR2, -1);
116 set_handler(SIGALRM, (__sighandler_t) alarm_handler,
117 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
118 SIGVTALRM, SIGUSR2, -1);
119 set_interval(ITIMER_VIRTUAL);
120}